Allegiance and Alliance
by Jewelia9
Summary: The unnatural world of the Olympians collides with the Avengers when Thor Odinson has a meeting with Percy Jackson. What will happen when these powerful people meet for the first time? What will happen when war is on the horizon? To whom will they pledge their allegiance and will they find unlikely alliances?
1. Chapter 1

**Hello : ) So, I've decided to combine two of my favorite things - PJO and the Avengers/Marvel Movies. This is a rough draft/rough story. I write to relax, so revision/editing wasn't really a priority today. I may make additional edits along the way. Please tell me what you think and if you have any ideas/requests. **

...

Thor read the parchment letter, scribbled in ancient Greek, as he paced back and forth in Stark Tower's meeting room. Upon his arrival on Midgard he told JARVIS to assemble all the Avengers.

"Thor, if you were mortal I'd kill you," Tony collapsed on a couch, wearing some rather embarrassing PJ's. "I know you're not one to remember the timetables of planet Earth, but 2AM is not the right time for a conference call."

"I figured_ you_ of all the Avengers would be awake at this hour. But, never mind the time, this is a matter of universal politics," the God of Thunder continued to pace as he waited for his pop-tart to launch out of the toaster.

"Universal politics? Like, more aliens? I could care less. You should've let me sleep."

Clint and Natasha walked into the room, attempting to stifle their own yawns. "Steve and Bruce are on their way to the tower," Natasha announced after she'd snatched a cup of coffee.

Thor hardly paid any of them any notice, even after he devoured his strawberry pop-tart. It wasn't until every member was lounging on a couch, or half-sleeping on the floor, that he broke the ominous silence.

"My father sent me down from Asgard to resolve a rather serious political issue. I'm not absolutely sure what I'm allowed to tell mortals, but if my father's right about the future I'm willing to take a few risks."

Natasha sat forward. "What type of politics Thor? Why are you so worked up?"

The god ignored the assassin and continued to talk aloud, almost to himself. "You've met my brother Loki and I, the personification of Norse mythology. But, I'm sorry to say, that we are not the only supernatural beings in this realm. We reside on another planet because our magic was too week to hide our presence on Earth," he paused, as if he was reluctant to add this last part. "And, we were ousted by other forces."

As Tony listened from the couch with his eyes closed, he made the weirdest facial expressions, until he finally sat up and, awake for the first time, interrupted Thor. "You're not making much sense buddy. Or maybe I'm still dreaming. You said something about universal politics? And then what does your father say about the future?"

"Yeah, please Thor. Make at least some sense. I'm half asleep and your monologue about aliens and mythology isn't doing anything to wake me up," Bruce said.

Thor grumbled to himself, then finally stopped pacing. "We are going to travel the coast to meet up with a few diplomats. My father sent me to make peace with them and o address his growing concerns about a universal war. I'm asking…I'm inviting all of you to come with me."

"Holy crap! Are you scared of these people Thor?" Tony almost coughed up his coffee at the idea.

"No!" Thor shouted unconcvincingly. "In fact, I respect them. It is just…I have not met them before and they have experienced a period of unrest recently. I am not scared, not even intimidated! I just think that if what my father says is true, it is about time you should meet them."

This time Steve raised his hand, to interrupt the god. "I'm going to ask the question we're all wondering about. Why exactly did you call us in the _middle of the night_? And who are we meeting exactly?"

"I want this first meeting to occur without Fury noticing. Also, they specified we meet as soon as possible."

They waited for him to continue, but he didn't. "Thor, who is _they_?" Steve asked again.

"We will meet them before sun-up. We leave in an hour."

…

"I was sleeping, actually sleeping. No nightmares," Thalia almost shrieked in rage. "If he was mortal, I'd kill him."

Percy and Nico just chuckled. "If he was mortal we'd _all_ kill him. Your dad is a pain in the ass," Nico said. Thunder and lightning crackled in the distance. "Sorry Uncle Zeus, you know we have no other choice but to love you!" Nico called back to the lightning and thunder which began to get closer.

"I'm just glad he didn't wake Annabeth," Percy whispered into the darkness.

The three demigods stood on the shoreline, ready to do the bidding of the gods. All of them had the tired look of people woken up suddenly in the middle of the night, and all of them wore equally frustrated and exhausted expressions on their faces.

Thalia suddenly began to move around. "Nico and I will wait in the shadows at first. We can give the Norseman a scare if you want to."

Percy nodded. "If you want to. I have a feeling he's going to bring more friends with him. He has aligned himself with the Avengers before."

"He's not going to be happy that he's meeting with us instead of our parents," Nico said, tracing his sword in the sand. "But I'm wondering – will he worship the almighty Percy Jackson? Or will he be an arrogant godly ass?"

Thalia nodded. "I'm sure they've heard rumors of the Titan and Giant Wars in Asgard. But, I'm also sure he's not going to like meeting up with teenagers."

"Hey, I am an adult," Percy insisted, pointing at his cousins, but without much conviction.

"Yeah, just keep telling yourself that Perce." Nico patted him on the shoulder before he shifted himself and Thalia into the shadows.

…

Natasha hid her confusion. She was confused with the way the god of thunder acted; she was confused about this strange meeting; and her confusion only grew when she met the strange figures on the beach.

"Who exactly are we going to meet here?" Steve asked Thor for the fifth time since they left the tower.

At first, they saw no one. But, as they walked down the isolated beach, she spotted a lone figure standing right on the shoreline, the waves just missing his feet.

The Avengers approached him, Thor wearing an increasingly guarded expression. Wearing converse, jeans and a white t-shirt, the casually dressed figure looked completely out of place standing before the uniformed Avengers.

Natasha had a hard time reading the young adult. His wore an expression that was as mischievous as it was mature. His black hair waved around with the restless sea breeze; his eyes calculated the approaching celebrities, while his mouth stayed in a smirk.

Natasha was able to hide her confusion way better than Tony and Bruce. They stood, coffee cups in hand, staring wide-mouthed at the boy on the beach. Thor hadn't really given them an idea of what to expect. Natasha expected a mystical unicorn more than she expected the random stranger she saw before her.

When they were within a couple yards of the boy, who stood unflinchingly in the same spot, Thor told them to stay put.

"What the hell Thor? Am I still dreaming? What's with the random kid on the beach?" Tony gestured around him with his coffee cup in hand, which looked especially odd since he was wearing his iron man suit.

The god ignored Tony as he took a few steps forward, towards the seeming stranger. And then bowed to his knees.

Tony dropped his coffee cup.

...


	2. Chapter 2

The boy on the beach – because, compared to the immortal Thor and the elderly Captain America the young adult standing on the shore was _a boy_ – the boy on the beach just watched as Thor knelt before him. The god maintained his guarded, brooding look as he stared at the figure from his subservient position on the sand.

"I, Thor Odinson, speak for the rest of Asgard. We pledge our fealty to you and your kind," Thor spoke into the awkward silence. The kid on the beach raised his eyebrows slightly at the formal greeting, though he didn't invite Thor to stand right away.

The kid simply nodded. He ran his hand through his hair, blinked a couple times, then, indifferently, motioned for Thor to rise. Natasha mentally gave the kid points for acting so casual in front of the fully armored Thor Odinson, god of thunder. Not to mention the Avengers standing behind him.

"I, Perseus Jackson, ambassador of the Earth, acknowledge your pledge of fealty." Perseus looked rather amused at this point, almost smiling (or laughing) outright at the uncomfortable god.

Thor cleared his throat and narrowed his eyes apprehensively. "Should I be insulted?"

The boy's amused expression vanished for the first time as he narrowed his eyes. "And what is so insulting about my presence Thor?"

Thor sighed and raised his hands in surrender. "Nothing, sorry for insinuating anything. I have heard a great deal about you in Asgard and I respect your noble deeds. I just – "

"_You just_ can't take me seriously without also taking a serious blow to your pride? Is that it?" Thor stiffened at the accusation, and the boy's expression softened. "Look, were you really expecting _them _to come down to meet you?"

Thor ignored the possible insult in his words. "There is a threat of universal importance – "

"Which _they_ are completely aware of. Which is why they sent me. At the crack of dawn. To have a diplomatic meeting. With an alien. And a bunch of costumed vigilantes." His smirk resembled more of a grimace at this point. "I accept your fealty Thor, and so do they." He reached his hand out and, when Thor grasped it with his immortal strength, he didn't so much as flinch.

"I do not wish to take this new threat lightly," Thor announced as he released his hold on the young man's hand.

"And neither do we; I'm willing to meet with you again, as soon as possible, to discuss what your allegiance means and the possibility of a military alliance."

Two teenagers, a boy and a girl, materialized behind Perseus as he was talking.

"Right, and this time, I'd really appreciate it if we didn't have to wake up in the middle of the night?" the girl interrupted casually, twirling an arrow like a baton. Her spiked black hair seemed to crackle in the lightning charged air.

Thor didn't so much as cough at their random appearance. "Of course. And, give your father my regards." Thor shifted his attention to the young boy that stood in Perseus's shadow. The god seemed to suddenly realize who the boy was before he suddenly spluttered, "May I ask for your blessing, Ghost King?"

The boy couldn't have been older than fifteen, yet he gave the god a dark smile. "I will do what I can to protect your immortal life force while you're on Earth." He raised his eyebrows, "Does this satisfy you?"

Thor nodded.

"Right. As lovely as this meeting was, I'm exhausted." Perseus glanced at the Avengers behind Thor. " I'll meet you at the Avengers tower tomorrow evening to discuss this threat." He stared Thor in the eyes, "I hope there are no hard feelings." Then all three of them vanished into thin air.

…

"I'm so confused!" Tony whined.

Thor was surprised his teammates had remained quiet while he talked with the Halflings on the beach. But now, he didn't quite know how to answer their questions.

"I will try to answer your questions as best I can – "

"Should we be preparing a defense against these people Thor?" Steve asked. "Anybody that has you bowing before them must be dangerous."

"I was not bowing!" Bruce sent him a pointed look. "Alright, I was. But it was just a necessary show of allegiance! Whether I like it or not, they hold the power in this realm."

"I'm so confused!" Tony whined. Again.

"Why don't you start by telling us who they are, Thor?" Steve suggested.

"Fine. From the way he acted around you, I do not think they would mind if I told you. Today you met a few of the greatest heroes of this time. I venture to say that they deserve even greater honor than all of the Avengers."

"I beg to differ," Tony muttered under his breath.

"I am a Norse god. We Norsemen had to relocate to another planet a few centuries ago because we were unable to maintain our position on earth. Our magic was not strong enough to conceal our presence." Thor clenched his fist, "And we were ousted from our position by the Greeks, and then the Romans."

"Wait, so you're saying _humans_ were powerful enough to drive you off the planet?" Steve asked, incredulous.

"No. The Greek and Roman _gods_."

Natasha hid her shock with a sly smile, while, on the inside, she could barely comprehend Thor's announcement. Tony, on the other hand, nearly fell out of his chair; he shouted, "Thor, I'm even more confused! More gods? Bruce, do a psych check on him!"

"Wait. So those were…those were Greek gods?" Clint tried to act casual as he asked the question that everybody was wondering. But as he tried to _casually_ drink his water, he missed his mouth and spilt it all over Natasha.

"No." Thor sighed in exasperation. "Those were demigods. Very powerful ones."

"I'm still confused. Those were _kids._" Tony put in.

"You would do well not to underestimate them. The gods allow their children to represent them in every way, even in diplomatic meetings…and even in war. Those _kids_ on the beach are three of the most powerful demigods alive."

"So I'm guessing fighting against them would be a bad thing," Steve suggested. "If they're not the problem, what about the threat you talked about? They didn't seem too concerned about it on the beach. They just seemed irritated."

"They would not be concerned. They've fought in two wars already. Dangerous threats are nothing new to them." Thor said this casually but the rest of the Avengers did a double take.

"Wait. So, super powerful, scary kids; more gods; wars that I've never heard about; dangerous threats." Tony counted these off on his fingers. "I'm less confused now. But who was the big kid? Was he the demigod king or something?"

"Big Kid? I am sure he would be amused to hear you call him that. And he's not really their king. But he is _the_ most powerful demigod on earth, at least, that's what most would tell you. But, I'm sure he will tell you more about himself tomorrow night. For now, I must report to the All Father on Asgard."

…

"C'mon. C'mon. Aha! Got it." Tony clapped his hands like a child.

"What is it?" Bruce asked.

"Well, I'm too curious to wait for tomorrow night to figure out more about the beach boy. So, I found some juicy info on him online. And then I was hoping Natasha and Clint could trail him tomorrow…"

"So you're stalking him?" Steve asked as he walked into the lab.

"And you want us to stalk him." Clint guessed.

"Exactly. Look. Apparently he…Whoa. He was involved in a manhunt. What the – and explosions at his school." Tony tried to scroll down the page but his computer froze. And then the information vanished. "It just disappeared! I was just getting to the good stuff…"

"Maybe he's trying to clean up anything about him off the web, now that he knows we know about him. He sounds like he has a sketchy past," Bruce suggested.

"Alright, now I'm a bit curious. Clint and I will trail him tomorrow morning. See what we find out," Natasha said.

…


	3. Chapter 3

"Nice bike." Steve looked over Tony's shoulder at the computer screen.

Natasha wore a mini-camera that transferred real time footage of everything she was seeing. She and Clint had followed a lead that reported Percy leaving an apartment on a motorbike.

"Yeah, it's fancy looking. Black leather jacket, nice helmet. I commend the guy's taste," Tony commented, biting out of an apple.

Perseus biked to a nearby coffee shop. Natasha sat in a corner booth; she watched as he ordered a Chai Tea Latte and two iced Carmel Macchiatos, telling the Barista his name was Percy.

"That's definitely not as intimidating as Perseus," Bruce noted.

When Percy glanced outside, Natasha's vision shifted to the door. A tall, buff Asian kid entered the coffee shop and gave Percy a bear-hug. They sat at a table a distance from Natasha and Clint. The bear-hug guy took one of Percy's coffees.

"It's so good to see you Frank." Percy was grinning ear-to-ear. Natasha noticed he looked far less intimidating when he was relaxed. "How's Hazel?"

Frank blushed. "Um. She's good. She wanted to come but she had to stay to help Reyna." He looked at Percy seriously for a moment. "I can tell when you're tense Perce. What did you want to talk to me about?"

Percy's face dropped, and his smile disappeared for a moment. Neither smug nor smiling, he just looked exhausted. "Well, we've encountered the Titan, Gaea and the Giants." He laughed darkly to himself. "But I don't think it's over quite yet."

Frank blanched. "What do you mean?"

"More disturbed primordial beings. My father had a chat with me a few days ago. Apparently there have been signs of chaos in the universe. But not just chaos…Chaos." When he saw Frank's confused look he admitted, "I didn't understand it either. But then I talked to Annabeth…"

"I'll do my research. Just tell me what you need and I'm there."

"Right, just, whatever you find. Keep it between the Praetors for now. I want to keep the peace as long as possible." Percy tapped a random, urgent beat on the table. Then he announced, clearly ready to change the subject, "So, have you heard from Jason and Piper lately?"

Natasha asked Clint, "Did any part of that conversation make sense to you? Chaos? Primordial beings?"

"Nope, but for all of his swagger, he seemed pretty anxious to change the subject." Natasha nodded.

"Jason and Piper are staying in New Rome for another day or two. What are you going to do today Perce? You seem pretty worked up. Get your mind off everything; go to the beach or the pool or something."

Percy chuckled. "Yeah, you know me too well. But I can't go to the beach. There's too much to do. I have to pick up Silena from Leo's shop. Talk with him about his new blueprints for the new yachts. I'm watching Silena all day until her parents get back from New Rome this evening, and then I'm meeting up with the Avengers this evening."

Frank shook his head. "You're too busy for your own good Percy. But hopefully Silena will keep your mind off everything, she's a cutie." After an awkward pause he asked, "Will I get to meet the Avengers?"

"Of course! Gods, I'm not hogging them or anything. In fact, I'm really not looking forward to this new role of ambassador or diplomat or whatever. But apparently they," he pointed to the ceiling, "think I'm _likeable_. Whatever the hell that means." He continued to tap his fingers on the table anxiously. "Thalia and Nico were supposed to come with me tonight but that didn't work out…They're busy."

"It's really starting again, isn't it?"

Percy nodded. "Thalia was called to a last minute hunt and Nico was called underground, I can only assume something's wrong down there." He wiped his hands over his face. "I don't want to involve everybody in this conflict. Not again. We're just recovering from our latest losses. I don't want to place more kids in the line of fire. That means The Seven will probably have to be especially involved if we don't want to call the next generation of campers to the front lines." He suddenly gave Frank a bright smile, "On the bright side, you get to meet the Hulk!"

"Yeah, I'm not that excited anymore…"

Percy's phone rang. His ringtone, the song Under the Sea from The Little Mermaid, made Frank smile. "Crap, it's Silena. Leo's probably torturing her in his shop. I'll see you later man."

…

Tony's voice sounded from Natasha's earpiece. "Perseus, or Percy. Whatever. He likes coffee. That's one thing we've learned today."

Natasha snorted. "I have a feeling we learned a lot more than that. It's just not clear to us yet." She waited until Percy bolted out of the coffee shop and jumped onto his motorcycle. "I placed a tracking device on his bike. So we can follow him casually to wherever he's heading. We can find out who Silena is…and then maybe we should call it a day. I feel like we're infringing on his privacy more than finding anything out."

Clint gave her a pointed look. "Are you really having qualms about spying on him?"

Tony guffawed in her earpiece. "You do remember that you're a _spy_ right?"

"Shut up assholes. You saw the way Thor acted around him. He treated this man with respect for a reason. I don't think getting on his bad side is a good idea…and if we're going to be working with him for a while…" Natasha stopped herself. She was starting to sound like Steve.

….

Percy maneuvered his way through the busy city streets until he reached Leo's shop. The sign read _Athena and Archimedes_. Calypso stood outside wearing grubby work clothes as she scrubbed the windows.

Right after the Giant War Hephaestus allowed his teenage son to start a commercial business. Out of all The Seven, excluding Annabeth, Leo was the entrepreneur. He worked small projects at first, but his inventions were starting to take the city by storm and, soon, large buyers were bound to start turning to _Athena and Archimedes._ When Annabeth wasn't working on Olympus she worked at Leo's shop. In the past year since the end of the Giant War she'd sold some pretty impressive building designs.

A few months ago, Percy and Leo were reliving memories from the Argo II (there may or may not have been underage drinking involved with this late night nostalgia). They both realized how much they missed the ship (Leo may or may not have broke down to tears as he remembered his precious, now deceased, ship). And with the encouragement of Annabeth, they started a charter/tour company. Leo built and designed the ships and Percy would take New York City residents and tourists along the coast. They were going to expand the company to the west coast, so Percy could work boat charters or tours whether he was needed at Camp Half Blood or Camp Jupiter.

Percy stopped his bike across the street. He then proceeded to run up and scare Calypso from behind. She screamed, flipped around and slapped him with her rag.

"Holy Hera! Could you not do that every time I see you Percy? You're going to give me a heart attack one day and I swear – "

"Uncle Percy! He's after me…" Silena ran out of the door and latched herself onto Percy's right leg.

Leo followed her out of the shop, screwdriver in hand, apparently intending to…

"What are you doing Leo?" Calypso asked, giving her boyfriend an incredulous look.

"Um. Nothing. She was…she started…I'm going back inside."

Silena detached herself from Percy's leg and ran back inside the shop shouting, "I'm gonna get my helmet."

Percy gave Calypso a brief, one sided hug before following his goddaughter inside shouting, "I have to look at some of Leo's stuff before we go Lena…"

He found Leo standing at his desk (his desk was as big as an eight-person dining table, but Percy didn't judge) "Percy, that is the last time I'm agreeing to watch Silena. You're her godfather. You get to watch her. I swear, she is worse than her mother…"

"What did she do this time?" Percy started to lean across the desk, eying a few blueprints, but Leo shoved him away.

"First off, stay at least two feet away from my desk at all times. Second, what _didn't _she do? She somehow got her hands on some scorpions and placed them all over my shop. And then, she's been doing this thing where she follows me around and mimics me. She copies everything I do just because she knows it gets on my nerves…"

"I always thought you'd be great with kids, but man.."

Leo shot his arm forward, screwdriver in hand, so Percy was staring cross eyed at the sharp blade of Leo's favorite tool. "I frickin' love children. Just not Clarisse's devil child."

"Well, she's an angel when she's with me so..." Leo looked like he was ready to explode. He really didn't like scorpions. "Anyways. Where are the blueprints?"

…

Chris and Clarisse got married during the Giant War, while Percy and Annabeth were in Tartarus. Clarisse was never one for sentimentality so she didn't think to wait until Percy and Annabeth were home. And, personally, Percy figured the Daughter of Ares thought there was something romantic about getting married during a war…

She had Silena shortly after. She was about three now and she looked like an Aphrodite version of her mother. Hence her name.

Percy was touched that Clarisse decided to name him and Annabeth Silena's godparents. Clarisse acted all exasperated when he asked her about it one day. She said, "I want her to have strong role models. And whether I like it or not Prissy, you're a warrior."

…

Natasha and Clint watched wide mouthed from across the street as Percy and a little girl wearing a blood-red helmet with boar tusks on it rode off towards the harbor.

"Is that legal?" Clint whispered. He didn't ask whether it was safe. It wasn't safe. A three year old didn't belong on a motorcycle in city traffic.

"I don't know but that kid is a natural. She's not even scared. But what's with her helmet?"

"Should we call the police?" Clint asked.

…


End file.
